According to Merriam-Websters dictionary, Chemistry is defined as “a science that deals with the composition, structure, and properties of substances and with the transformations that they undergo” which is closely related to the definition of Physics “a science that deals with matter and energy and their interactions”. Chemistry is significant because it is the base of many other sciences, many important discoveries are due to the scientific advances in chemistry. Chemistry and matter plays a role in everyday life, such as battery base electronics and other daily cleaning supplies. Chemistry is also at the heart of environmental sciences, which the periodic table is important to. Chemistry defines what makes a piece of matter a nutrient or a mineral. Chemistry applies to health supplies also, and helps save many lives everyday. The chemistry of different medicines decides which drugs and vitamins help with each disease, and other illnesses.
http://www.gregb.co.uk/chem/home.asp
http://chemistry.about.com/od/chemistry101/f/importanceofchemistry.htm